Rollup of 9 pull requests
Successful merges:
- #121958 (Fix redundant import errors for preload extern crate)
- #121976 (Add an option to have an external download/bootstrap cache)
- #122022 (loongarch: add frecipe and relax target feature)
- #122026 (Do not try to format removed files)
- #122027 (Uplift some feeding out of `associated_type_for_impl_trait_in_impl` and into queries)
- #122063 (Make the lowering of `thir::ExprKind::If` easier to follow)
- #122074 (Add missing PartialOrd trait implementation doc for array)
- #122082 (remove outdated fixme comment)
- #122091 (Note why we're using a new thread in `test_get_os_named_thread`)
r? `@ghost`
`@rustbot` modify labels: rollup
On modern Linux with Intel AMX and 1KiB matrices,
Arm SVE with potentially 2KiB vectors,
and RISCV Vectors with up to 16KiB vectors,
we must handle dynamic signal stack sizes.
We can do so unconditionally by using getauxval,
but assuming it may return 0 as an answer,
thus falling back to the old constant if needed.
If it's obvious from the actual syscall results themselves that the
syscall is supported or unsupported, don't do an extra syscall with an
invalid file descriptor.
CC #122052
This test won't work on windows 7, as the Thread::set_name function is
not implemented there (win7 does not provide a documented mechanism to
set thread names).
Some implementations of `Write::write_vectored` in the standard
library (`BufWriter`, `LineWriter`, `Stdout`, `Stderr`) check all
buffers to calculate the total length. This is O(n) over the number of
buffers.
It's common that only a limited number of buffers is written at a
time (e.g. 1024 for `writev(2)`). `write_vectored_all` will then call
`write_vectored` repeatedly, leading to a runtime of O(n²) over the
number of buffers.
The fix is to only calculate as much as needed if it's needed.
Cleanup windows `abort_internal`
As the comments on the functions say, we define abort in both in panic_abort and in libstd. This PR makes the two implementation (mostly) the same.
Additionally it:
* uses `options(noreturn)` on the asm instead of using `core::intrinsics::unreachable`.
* removed unnecessary allow lints
* added `FAST_FAIL_FATAL_APP_EXIT` to our generated Windows API bindings instead of defining it manually (std only)
Use the OS thread name by default if `THREAD_INFO` has not been initialized
Currently if `THREAD_INFO` hasn't been initialized then the name will be set to `None`. This PR changes it to use the OS thread name by default. This mostly affects foreign threads at the moment but we could expand this to make more use of the OS thread name in the future.
Note: I've only implemented `Thread::get_name` for windows, linux and macos (and macos adjacent) targets. The rest just return `None`.
fix typo in documentation for std::fs::Permissions
Please check and re-check this PR carefully to see if I got this right.
But by my logic, if the `read_only` function returns `true`, I would not expect be able to write to the file (it being read only); so this text is meant to clarify that `read_only` being `false` doesn't mean *you* can actually write to the file, just that "in general" someone is able to.
The new interface has some similarities to Linux system call
getdents64. The system call reads several dirent64 structures.
At the end of each dirent64 is stored the name of the file.
The length of file name is implictly part of dirent64 because
d_reclen contains size of dirent64 plus the length of the file
name.
Delete architecture-specific memchr code in std::sys
Currently all architecture-specific memchr code is only used in `std::io`. Most of the actual `memchr` capacity exposed to the user through the slice API is instead implemented in `core::slice::memchr`.
Hence this commit deletes `memchr` from `std::sys[_common]` and replace calls to it by calls to `core::slice::memchr` functions. This deletes `(r)memchr` from the list of symbols linked to libc.
The interest of putting architecture specific code back in core is linked to the discussion to be had in #113654
Use volatile access instead of `#[used]` for `on_tls_callback`
The first commit adds a volatile load of `p_thread_callback` when registering a dtor so that the compiler knows if the callback is used or not. I don't believe the added volatile instruction is otherwise significant in the context. In my testing using the volatile load allowed the compiler to correctly reason about whether `on_tls_callback` is used or not, allowing it to be omitted entirely in some cases. Admittedly it usually is used due to `Thread` but that can be avoided (e.g. in DLLs or with custom entry points that avoid the offending APIs). Ideally this would be something the compiler could help a bit more with so we didn't have to use tricks like `#[used]` or volatile. But alas.
I also used this as an opportunity to clean up the `unused` lints which I don't think serve a purpose any more.
The second commit removes the volatile load of `_tls_used` with `#cfg[target_thread_local]` because `#[thread_local]` already implies it. And if it ever didn't then `#[thread_local]` would be broken when there aren't any dtors.
add platform-specific function to get the error number for HermitOS
Extending `std` to get the last error number for HermitOS.
HermitOS is a tier 3 platform and this PR changes only files, wich are related to the tier 3 platform.
Implement unwind safety for Condvar on all platforms
Closes#118009
This commit adds unwind safety consistency to Condvar. Previously, only select platforms implemented unwind safety through auto traits. Known by this committer: On Linux, `Condvar` implemented `UnwindSafe` but on Mac and Windows, it did not. This change changes the implementation from auto to explicit.
In #118009, it was suggested that the platform differences were a bug and that a simple PR could address this. In trying to determine the best information to put in the `#[stable]` attribute, it [was suggested](https://github.com/rust-lang/rust/issues/121690#issuecomment-1968298470) I copy the stability information from the previous unwind safety implementations.
Increase visibility of `join_path` and `split_paths`
Add some crosslinking among `std::env` pages to make it easier to discover `join_paths` and `split_paths`. Also add aliases to help anyone searching for `PATH`.
Closes#118009
This commit adds unwind safety to Condvar. Previously, only select
platforms implemented unwind safety through auto traits. Known by this
committer: Linux was unwind safe, but Mac and Windows are not before
this change.
Extending `std` to get the last error number for HermitOS.
HermitOS is a tier 3 platform and this PR changes only files,
wich are related to the tier 3 platform.
